Compound of magnesia.



UNITE STATES PATENT Qrrlcn.

EM L RUEFF, on NEW YORK, N. Y.-

. COMPOUND MAGN'ESIAI SPECIFICATION forming part of Letters rete t ve. 694,424, Wed March 4, 1902.

Original application filed August 3, 1898, Serial No. 687,595. Divided and this application filed August 7,1899. Serial No. 726,409. (1T0 specimens.) Y

To all whom it may concern:

Be it known that I, EMIL RUEFF, a resident of the city of New York, borough of Manhattan, county and State of New York, have invented an Improved Fireproofing and Heat and Sound Insulating Compound, of which the following is a specification.

This invention relates to'improveinents in 7 June 23, 1899, which itself is a division of my application, Serial No. 687,595, filed August 3, 1898, which resulted inPatent No. 630,115. It is therefore to be understood that this application is a division of my said application, Serial No. 687,595.

. inafter claimed.

which latter formula also represents the composition of heavy carbonate of magnesia of commerce. The mineral magnesite MgOOO is the normal carbonate of magnesia. The basic or alkaline carbonates which I produce contain more water and lessacid in proporceed' in various ways.

This new carbonate of magnesia I shall hereinafter designate as alkaline magnesite.

Inproducing alkaline magnesitel may pro- One way to produce alkaline magnesite is as follows: I mix one part of powdered calcinedlmagnesite with twenty parts of water and conduct to such mixture, while in a state of agitation, carbonic-acid gas under a pressure of about twenty-five pounds per square inch until the mixture 7 has absorbed less than one part, by weight, of the carbonic-acid gas, so as to prevent the My invention consists in the article here-' formation of a normal carbonate of magnesia. The whole mass is then heated gradually to a temperature less than or preferably to about 160 Fahrenheit, drained, dried, and may then be compressed under a pressure of from two hundred to one thousand pounds per square inch into the desired shape. The article thus obtained is a carbonate of magnesia which contains in proportion to the MgO less carbonic acid and more chemically-bound water than any other commercial carbonate of magnesia heretofore produced. The alkaline mag- Y nesite thus obtained differs from-the ordinary magnesite in that it contains in proportion to its magnesia less carbondioxid than ordinary magnesite and also in that it contains.

chemically-combined water,which is not present in ordinary magnesite. magnesite is a heavy and dense mineral,while the article which I produce is a Very finely divided and light product,whioh forms porous lumps in the presence of water. The excess The ordinary of chemically-bound water and the method of preparing the mass vastly improves the condition of the substance. It is very light in weight, and, unlike all other articles of the same class, it possesses great tensile strength and elasticity and is able to withstand not only the roughest handling, but also the severest test to which any building material used for lining interior walls, ceilings, &c., may be subjected. This substance has great resistance to the influence of heat and may be used for fireproofing, and being a non-conductor of sound may be also used as an isolating-lining for covering walls, ceilings, iceboxes, safes, &c., and may be used as a pipe or boiler covering.

\rVhat I claim, and desire to secure by Letters Patent, is-

elasticity.

EMIL RUEFF. Witnesses:

MAURICE BLOCK, GEO. E. MORSE. 

